High Speed Synchronous
N-Channel MOSFET Driver

The LTC4447 is a high frequency Gate driver with integrat-
ed bootstrap SchottkyDiode that is designed to drive two
N-Channel MOSFETs in a synchronous DC/DC converter.
The powerful Rail-to-Rail driver capability reduces switching
losses in MOSFETs with high Gate capacitance.
The LTC4447 features a separate supply for the input Logic
to match the signal swing of the controller IC. If the input
signal is not being driven, the LTC4447 activates a shut-
down mode that turns off both external MOSFETs The input
Logic signal is internally level-shifted to the bootstrapped
supply, which functions at up to 42V above ground. The
SchottkyDiode required for the bootstrapped supply is
integrated to simplify layout and reduce parts count.
The LTC4447 contains undervoltage lockout circuits on
both the driver and Logic supplies that turn off the external
MOSFETs when an undervoltage condition is present. An
adaptive shoot-through protection feature is also built-in
to prevent the power loss resulting from MOSFET cross-
conduction current.
The LTC4447 is available in the 3mm 3mm DFN
package. By Linear Technology Corporation